I upgraded the devotion (intel core duo mac mini) to 2gb of ram today, it really was much easier than everyone said it would be, and it saved $250 over letting Apple do it (took me 25 minutes).

Also, I had forgotten about proxy arp, which I think might be a better solution than bridging. The bridge puts both interfaces in promiscious mode and doesn't let me firewall the traffic (the ebfilter stuff is in 2.6 and dd-wrt ships with a 2.4 kernel). With proxy arp i will get the same effect and ability to fliter out DHCP requests from the outside.